1. Technical Field
This invention relates generally to a method and apparatus to simulate rotation of a vehicle wheel to facilitate vehicle testing.
2. Description of the Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
Testing of various types of vehicle systems sometimes involves simulating rotation of a vehicle wheel. For example, U.S. Pat. No. 5,594,173 to Frey discloses a test device configured to stimulate a wheel speed sensor of an automotive vehicle. The test device includes a wheel rotation simulator that includes a magnetic coil, and a control unit that applies AC voltage to energize the coil to magnetically stimulate the vehicle's wheel speed sensor to sense a simulated wheel speed. Frey discloses the use of the simulated wheel speed input in carrying out functional tests of such vehicle systems as cruise control and speed-sensitive windscreen wipers. Also, Frey teaches that functional tests of brake control systems necessitate actual wheel rotation. Frey therefore discloses a transportable roller unit that supports and actually rotates a vehicle wheel at speeds necessary to provide a wheel speed input necessary to test a vehicle brake system.
U.S. Pat. No. 5,005,405 to Ishizeki discloses a method of testing a vehicle's anti-lock brake control system. The method includes mounting such a vehicle on a test stand having rollers that support and impart rotational motion to the vehicle's wheels. The test stand also includes a dynamometer that measures braking force.
U.S. Pat. No. 6,425,282 to Vaughn discloses a portable test device for a rail car air brake system. The test device includes ports connectable to a source of pressurized air and to a brake pipe connector, valves that selectively interconnect the ports to each other and to the atmosphere as necessary to perform tests, a sensor that measures pressure at a brake pipe port of the test device, a controller coupled to the valves and sensor, a housing, an input device, and a display.
U.S. Pat. No. 7,489,996 to Gowan discloses an aircraft wheel anti-skid system including wheel speed transducers that provide wheel speed data to axle-mounted antiskid units. The system also includes radio frequency data ports that download wheel speed data from the antiskid units, a transmitting antenna disposed at the axle, and a receiving antenna disposed at a wheel of the aircraft. A laptop computer can be interfaced with the data port to download data.
U.S. Pat. No. 6,837,553 to Beck discloses an aircraft anti-skid brake control system, an aircraft nose wheel steering control system, and a built-in test system. The built-in test system includes a field programmable gate array (FPGA) that executes system algorithms. The built-in test system also includes a wheel speed interface that's interposed between the FPGA and wheel speed transducers and presents simulated wheel speed signals to the FPGA for use in testing the anti-skid and nose wheel steering systems.
U.S. Pat. No. 5,020,861 to Gorges discloses a cap that attaches to an aircraft wheel in a position covering a hub of the wheel. An inside surface of the cap includes a means for engaging a hub-mounted antiskid system wheel speed transducer in such a manner that rotation of the wheel and cap is transmitted to the transducer. The cap is disposed relative to the wheel hub such that an airflow passageway is formed between the transducer and a sidewall of the cap.